Proteomic analysis of osteoclast lipid rafts: The role of the integrity of lipid rafts on V-ATPase activity in osteoclasts

Jiyoon Ryu, Hyunsoo Kim, Eun Ju Chang, Hyung Joon Kim, Youngkyun Lee, Hong Hee Kim

Research output: Contribution to journalArticlepeer-review

6 Scopus citations

Abstract

Lipid rafts are membrane platforms for signaling molecules that regulate various cellular functions. During osteoclastogenesis, lipid rafts also have been shown to play a crucial role for cell fusion upon RANK/RANKL interaction and further activation of osteoclasts, resulting in bone resorption. To investigate proteins that localize inlipid rafts, we conducted two-dimensional (2D) gel electrophoresis followed by MALDI-TOF mass spectrometry. We identified 12 functional proteins among 34 proteins that were detectable by silver staining of the 2D gel. Among them, a subunit of vacuolar H+-ATPase that is involved in resorption activity of osteoclasts was identified showing an approximate molecular weight of 56.94 kDa and pI of 5.4. The solubilization of osteoclast membrane proteins followed by sucrose density gradient fractionation confirmed that V-ATPase colocalized with flotillin-1, a marker of lipid rafts, in low-density detergent-insoluble fractions. Disruption of rafts with cholesterol-sequestering agents or introduction of a dominant-negative mutant of TRAF6 impaired V-ATPase activity. These data indicate that integrity of lipid rafts regulates the activity of V-ATPase in osteoclasts, suggesting that cholesterol-lowering agents might be useful for inhibiting osteoclast-dependent bone resorption.

Original languageEnglish (US)
Pages (from-to)410-417
Number of pages8
JournalJournal of Bone and Mineral Metabolism
Volume28
Issue number4
DOIs
StatePublished - Jul 2010
Externally publishedYes

Keywords

  • Lipid rafts
  • Osteoclasts
  • Proteomics
  • Resorption
  • V-ATPase

ASJC Scopus subject areas

  • Endocrinology, Diabetes and Metabolism
  • Orthopedics and Sports Medicine
  • Endocrinology

Fingerprint Dive into the research topics of 'Proteomic analysis of osteoclast lipid rafts: The role of the integrity of lipid rafts on V-ATPase activity in osteoclasts'. Together they form a unique fingerprint.

Cite this